Method of making chain links



Dec 22, 1931. R E WALDRON 1,838,025

METHOD OF MAKING CHAIN LINKS Filed Dec. 22, 1924 2 Sheets-Sheet l z Adanvemtoz D86. 22, 1931. WALDRON 1,838,025

METHOD OF MAKING CHAIN LINKS Filed 1924 2 Sheets-Sheet 2 71 vsnscll 15fWi r z Patented Dec. 22, 1931 V PATENT OFFICE RUSSELL E. wALDnon,ornnrnorr,

MICHIGAN, ASSIGNOR T DOMINION ronen &

STAMPING COMPANY, LIMITED, OF- WALKERVILLE, ONTARIO, CANADA, A CORPO-BATION OF ONTARIO, CANADA 1 METHOD or MAKING CHAIN LINKS )7 Applicationfiled December 22,'1924.: Serial No. 757,505.

'Ihis'invention relates to chain links and particularly to a method ofproducing the same, 7

The invention contemplates the production of chain links provided withparallel surfaces by a die forging method wherebylinks for instance ofrelatively-large dimensions designed for use in conveyor chams and thelike may be cheaply and quickly man: ufactured.

The various objects and this invention will be made more apparent as thedescription proceeds especiallywhen considered in connection withtheaccompanying drawings wherein: e v

Figure 1 is a fragmentary PBISPBCUVB'VIBW of a chain'showing a linkconstructed in accordancewith the invention; 1

Figure 2 is a separated perspective View of the original forg ng dies; I

Figure '3 is a sectional view throughthe original forging dieswiththework'piece 1n position; i

Figure & is a perspective of the work piece after it leaves the originalforging dies; Figure 5 is a sectional view through the Y punching dieemployed forxtrimming tl1e flash or excess material from the workplece';

Figure -6 is a similar view showing the die parts and work piece afterthe trimming operation; 1 1

Figure 7 is a-sectiona'l view through the punching die employed forremoving the web from the center of the link;

Figure 8 is an enlarged sectional view showing the transverse shape ofthe link after it leaves the punching press shown in Figure 7' i Figure9 is a separated perspective view of the clamping'die andstretchingpunch employed for surfacing the ends of the link to produceparallel surfaces and Figure 10 is a sectional view showing'th'e partsillustrated in Figure 9 after-the operation upon the link. Y Y Referringnow particularly to the drawings' wherein like characters indicate likeparts, it will be noted that thereis illustrated in Figure 1 a sectionof a conveyor chain comprising link members 10 which are aladvantages ofternately arranged with link members formed by a pair of members 11,pivotal connection between the members 10 and 11 being provided by pivotpins 12 disengageably connected to the members 11. In practice thesurface 13- at each end of the link member 10 has a bearing engagementwith the pin 12 of each link while the exterior end surfaces 14: of eachlink member 10 are engageable by the teeth of the sprocket wheel (notshown). r

He'retofore the practice has been in general to forge or cast the linkmembers 10 with substantially centrally arranged longitudi nallyextending inner and outer draft or bevelportions 15 and 16 respectively.In order toremove these raised portions and produce a suitable bearingsurface on the inner ends 13 of the links the latter were usuallymachined at this point, while in many instances no cons deration wasgiven to the outer end surface 14 that engaged the teeth of the sprocketwheel. The result of this practice was that the cost of production ofthe links 10 was materially increased as well as the time required formanufacture. Furthermore, the constant engagement of the bevels ordrafts 16 with the teeth of the sprocket Wheel proved costly in thatthis action occasioned unusual wear to I the teeth. 7

An important object of this invention is therefore to produce chainlinks substantially similar to the links 10 bya die forging method.Another object is to provide means, during the production of the linksfor redistributing the metal wat the ends of the link and for so shapingthese ends as to produce parallel interior and exterior surfacesaffording satisfactory bearing surfaces for the pins 12 and for theteeth of the sprocket wheel. 7 w

In practicing this invention a forging 'die similar to that illustratedin Figures 2 and dis preferably employed comprising upper and lower diemembers 17 and 18 between whicli'the blank is inserted to form a workpiece 19-such as shown in Figure 4. .In actual practice the'blank is inthe form of a bar, the end of" which is inserted betweenthe die members17 and 18 and after the formation of the work piece 19 it is sheared offfrom the remainder of the blank, on the next operation of the diemembers, by means of the shearing members 20 carried respectively by thedie members 17 and 18. v

The work piece as it comes from the original forging dies comprises inaddition to the main link body a circumferential flange 21 of excessmaterial or fiashing as well as a central web or slug 22.

In Figures 5 and 6 there is illustrated a punching die comprising upperand lower die members 23 and 24 by means of which the flashing 21 issheared off or removed from the outside of the work piece. {is will benoted from an examination of Figures 5 and 6, the work piece 19 isplaced upon the die member 24: andis, punched through this die member bythe upper dieinember "23 and the flashing vorexcess material 21 istrimmed while the central web thereof therefrom.

In Figure Tthereis illustrated a punching die comprising upper andlowercdie members 25 and 26 by means of which the web or slug in thecenter of the work piece is renewed. In carrying out this-operation thework piece 19 is supported upon the lower'die member is engaged by theupper die memberand removed from the work piece by a punching operation,I

The exterior conformation of the work iece or link at this stage isillustrated in igure 8. The draft or bevel on the outer and inner sidesof the link is shown,--somewhat exaggerated, for the purpose ofvemphasizingthe importance of the next. step of this method by whichthese vertical sides of the link, particularly at the ends thereof, .areflattened or straightened, by a redistribution of the metal, to forminner and outer bearing surfaces for the purpose hereinbefore mentioned.V I

InFigures 9 andlO the meansfor carrying out the last step of this methodis illustrated. For this purpose there is. preferably provided aclamping die composed of die members 27 and 28 into which the work pieceor link the manner clearly shown. The work piece or link rests in arecess formed by theslots 29 of the two die clamping members, the ends30 of this recess being squared with reference to the longitudinal axisof the recess whereby the ends of the link 19 when forced into e11gagement therewith will consequently be squared or flattened withreference to the longitudinal axis of the link To aflord means forhandling thework piece 19 and for protecting the same against theclamping action ofthe die clamping members 27 and 28 there is providedacombined handling tool and filler block 31 which may rest within alongitudinal depression 32 formed in the die members and longitudir ofthe link. As the stretching 19 is adapted to be placed, in

nally displaceable therein. At the beginning of this last stage of themethod this filler block 31 extends within and preferably through thework piece or link 19 as shown in Figure 9. The sides of the link arethere fore'prevented from collapsing so that no difliculty will beexperienced in forcing the stretching punch 33 into and through the holepunch 33 approaches the work piece it first engages the filler block 31and moves the same longitudinally from engagement with the work piece aswill be obvious;

The stretching punch 33 is preferably provided with a tapering forwardend 34 to facilitate the entrance of the punch into the hole of thelink, the, longitudinal edges 35 of this punch being parallel. Thevertical dimension of this punch, as seen in Figure 9, is such-asto-causea stretching or expansion of the work piece 19 within the recess29 of the clamping die. r v V Itwill beunderstood that the stretchingpunch acts principally upon the ends of the work piece, the engagementof this punch withthe inner end surfaces 13 causing a flattening orredistribution of themetal and a forcing'of the excess materialoutwardlywith the result that the outer end surfaces 14 are pressed upagainst the squared ends 30 of the work piece recess. Consequently theinner and. outersurfaces of the link, at the ends thereof, are renderedsubstantially parallel to .one another to form suitable bearingsurfaces. 1 V 7 By practicing-the herein described method chain linksand the like may be for-med by die forging and provided with suitablebearing surfaces without necessitating a machining operation whereby thecost and time of production is reduced to a minimum. While the methodhasbeen described as including several'distinct steps it will beimmediately obvious to those skilled in the art, thatlone or bined byproperly constructing the die members andto this end the inventioncontemplates such'modifications in the manner of executing the sameasmaycome within the purview of the accompanying claims.

What I claim as my invention is:

1. The method of links having their ends provided with parallel interiorand exterior surfaces which consists of die forging the link from ablank, removing the excess material by die punching and removing thedraft ,or bevel from the ends of the link by clamping the link in aclampingdie with the die embracing the ends of the link and forcing astretching punch intotheihole of the link. I

2. The method of producing forged chain links having their ends providedwith paralmore of the several operations may be com- .lel interior-andexterior surfaces which conproducing forged, chain removing the excessmaterial from the exterior and interior of the link and removing thebevel from the link at predetermined points by clamping the link in aclamping die with the die embracing the ends of the link and. forcing apunch into the hole of the link.

3. The method of producing forged chain links provided with parallelsurfaces which consists of die forging the link from a blank, removingthe excess material from the exterior and interior of the link andremoving the draft or bevel from the ends of the link by clamping thelink, mounted on a filler block, in a clamping die and subjecting thelink to the action of a stretching punch which displaces the fillerblock and enters the hole of the link. 7

In testimony whereof I aflix my signature.

RUSSELL E. WALDRON.

